From the Rolls-Royce experimental archive: a quarter of a million communications from Rolls-Royce, 1906 to 1960's. Documents from the Sir Henry Royce Memorial Foundation (SHRMF).
Article from 'Automotive Industries' magazine detailing the engine and features of the new Cadillac V-16.
| Identifier | ExFiles\Box 19\3\ Scan150 | |
| Date | 4th January 1930 | |
| Automotive Industries January 4, 1930 2 Cadillac V-16, Developing Between Has Complete Fuel System Separate piping, vacuum tank, carburetor valve silencer, eliminating tappet braking system are among the By ATHEL The front end of the Cadillac V-16, showing the decorative grill on the radiator, two horns and other refinements UNDOUBTEDLY one of the most interesting cars at the New York show will be the new Cadillac V-16, whose 16-cylinder 3 by 4-in. engine, with 5.5 to 1 compression ratio, is said to develop between 170 and 185 hp. at 3200 r.p.m. The car has an hydraulic take-up for the valve-gear, which does away with tappet noises and adjustments; a vacuum assister is applied to the braking system; crankcase ventilation is thermostatically controlled, and two complete fuel systems (piping, vacuum tank, carburetor and manifold) are provided, one for each cylinder block. Not only is the line of bodies offered with the chassis said to be very attractive and luxuriously appointed, but the chassis itself is finished to an unusual degree. The running gear is ground and enameled; springs are encased in metal coverings, and all accessories under the hood are concealed or “dressed up.” The engine structure is composed of eight castings, of which four are of aluminum alloy and the other four of nickel-iron. The former comprise the crankcase upper and lower sections and the covers for the overhead valves. To improve the oil cooling, the crankcase lower section is provided with longitudinal ribs. The four nickel-iron castings are the two cylinder blocks and the two cylinder heads. Cylinder barrels extend into the crankcase a considerable distance, which in conjunction with the small angle of the V, 45-deg., gives a rather compact engine. Owing to the short stroke (4 in.), and the large crankshaft (2 5/8 in.) and crankpins (2 1/8 in.), the crankshaft is quite rigid, but to make doubly sure of smooth operation it is provided with an harmonic balancer. Connecting rods are located side-by-side on the crankpins, the cylinder blocks being offset longitudinally. Main bearings are of the steel-backed, babbitt-lined type. Pistons, rings and pins are quite conventional, but the valve gear is a new departure. The single camshaft, for the sake of compactness, is located in the crankcase above the crankshaft, with pushrods operating the rocker arms over the valves, the latter being of the overhead type. To completely silence this mechanism in the engine, an hydraulic automatic valve silencer for valve and pushrod clearance is provided. This mechanism is shown in an accompanying drawing. It will be noted that each rocker arm is mounted on an eccentric whose lip presses on the top of a plunger in an oil dash pot. The plunger in turn is held against the eccentric by coil springs, while through it are drilled small oil relief holes. In operation this hydraulic valve lash-adjusting mechanism works somewhat as follows: Let us assume that there is some clearance in the valve mechanism. Owing to the upward pressure on the plunger in the dash pot, the plunger will rise, and rotate the eccentric bushing on the rocker arm shaft until the rocker arm has been lowered, with respect to the shaft center, an amount which will take up the valve clearance. Beyond that point it cannot push the eccentric bushing. Let us assume that it did, and that we had a negative clearance. Under these conditions there would be a constant upward spring pressure on both ends of the rocker arm. These forces, of course, balance themselves with respect to the center of the bushing, but the center of the bushing is to one side of the center of the shaft on which it is mounted. As the forces tend to balance each other about the shaft also the center of the bushing tends to move toward the center SECTION A A Details of the rear mounting of the Cadillac V-16 engine | ||